#!/bin/bash
#
# LibrePortal source-fetch helpers for the RUNTIME paths (update / reinstall /
# reset). They place a fresh copy of the code at $script_dir (the install tree,
# which holds ONLY code — configs/logs live in the separate system tree, so the
# install tree can be replaced wholesale).
#
# Three modes, keyed off CFG_INSTALL_MODE:
#   release  download a versioned, checksum-verified tarball over HTTPS (default)
#   git      clone (handled by the existing git_* helpers / initGIT)
#   local    copy from a local folder (existing copyFilesFromLocal)
#
# init.sh's initGIT does the FRESH-install fetch inline (it is self-contained for
# the bare /root reinstall copy); these functions are the sourced runtime twins.

# Release host + channel: env wins (testing), then config, then the public default.
lpReleaseBaseUrl() { echo "${LP_RELEASE_BASE_URL:-${CFG_RELEASE_BASE_URL:-https://get.libreportal.org}}"; }
lpReleaseChannel() { echo "${LP_RELEASE_CHANNEL:-${CFG_RELEASE_CHANNEL:-stable}}"; }

# Downloader + checksum tool detection (curl|wget, sha256sum|shasum).
_lpFetchTool() { command -v curl >/dev/null 2>&1 && { echo curl; return; }; command -v wget >/dev/null 2>&1 && { echo wget; return; }; echo ""; }
_lpDownload() {  # _lpDownload <url> <outfile|->
    local tool; tool="$(_lpFetchTool)"
    case "$tool" in
        curl) [[ "$2" == "-" ]] && curl -fsSL "$1" || curl -fsSL "$1" -o "$2" ;;
        wget) [[ "$2" == "-" ]] && wget -qO- "$1" || wget -qO "$2" "$1" ;;
        *) return 1 ;;
    esac
}
_lpSha256() { if command -v sha256sum >/dev/null 2>&1; then sha256sum "$1" | cut -d' ' -f1; elif command -v shasum >/dev/null 2>&1; then shasum -a 256 "$1" | cut -d' ' -f1; fi; }
_lpJsonStr() { printf '%s' "$1" | grep -oE "\"$2\"[[:space:]]*:[[:space:]]*\"[^\"]*\"" | head -1 | sed -E 's/.*"([^"]*)"$/\1/'; }
_lpJsonNum() { printf '%s' "$1" | grep -oE "\"$2\"[[:space:]]*:[[:space:]]*[0-9]+" | head -1 | grep -oE '[0-9]+$'; }

# Verify a downloaded file against a detached minisig using the ROOT-OWNED
# footprint public key (/usr/local/lib/libreportal/libreportal.pub). The key is
# in the footprint so the manager can't swap it to bless a forgery. Trust posture
# matches lpVerifyInstall (verify.sh): once the key is REAL (not the REPLACE_ME
# placeholder) a valid signature is MANDATORY; an unactivated/dev build skips it.
# This is the single trust anchor shared by the release fetch (lpFetchRelease)
# and the artifact-index fetch (lpFetchIndex, source/artifacts.sh).
#   Args: <file> <sigfile>
#   Returns 0 = OK to proceed (signature verified, OR signing not activated);
#           1 = REFUSE (key real but minisign missing / sig missing / sig invalid).
#   Echoes "verified" or "unsigned" for the caller's audit line.
lpVerifyMinisig() {
    local file="$1" sig="$2"
    local pub="/usr/local/lib/libreportal/libreportal.pub"
    if [[ ! -f "$pub" ]] || grep -q REPLACE_ME "$pub" 2>/dev/null; then
        echo unsigned; return 0
    fi
    if ! command -v minisign >/dev/null 2>&1; then
        isError "lpVerifyMinisig: minisign required to verify '$file' but not installed"; return 1
    fi
    if [[ ! -f "$sig" ]]; then
        isError "lpVerifyMinisig: signature for '$file' missing — refusing"; return 1
    fi
    if ! minisign -Vm "$file" -p "$pub" -x "$sig" >/dev/null 2>&1; then
        isError "lpVerifyMinisig: SIGNATURE INVALID for '$file' — refusing"; return 1
    fi
    echo verified; return 0
}

# Root-owned-footprint version: the one INSTALLED on this box (marker written by
# init.sh) vs the one the channel's latest release ships (manifest). When the
# latter is greater, a plain manager-run update can't apply it (it can't rewrite
# the root-owned helpers/wrapper/unit) — a root re-install is required.
lpInstalledFootprintVersion() { local v; v=$(cat /usr/local/lib/libreportal/.footprint_version 2>/dev/null | tr -d ' \t\n\r'); echo "${v:-0}"; }
lpReleaseLatestFootprint() {
    local m; m="$(_lpDownload "$(lpReleaseBaseUrl)/$(lpReleaseChannel)/latest.json" - 2>/dev/null)" || return 1
    local f; f=$(_lpJsonNum "$m" footprint_version); echo "${f:-0}"
}

# Resolve the latest published version of the configured channel (empty on failure).
lpReleaseLatestVersion() {
    local m; m="$(_lpDownload "$(lpReleaseBaseUrl)/$(lpReleaseChannel)/latest.json" - 2>/dev/null)" || return 1
    _lpJsonStr "$m" version
}

# Download + verify + extract a release into $script_dir. Arg: optional version
# (else the channel's latest). Returns non-zero (and leaves $script_dir untouched)
# on any download/checksum failure — callers must not proceed on failure.
lpFetchRelease() {
    local want_ver="${1:-}" base channel manifest tarname want_sha tmp tar got
    base="$(lpReleaseBaseUrl)"; channel="$(lpReleaseChannel)"
    [[ -n "$(_lpFetchTool)" ]] || { isError "lpFetchRelease: need curl or wget"; return 1; }

    if [[ -z "$want_ver" ]]; then
        manifest="$(_lpDownload "$base/$channel/latest.json" - 2>/dev/null)" || { isError "lpFetchRelease: cannot fetch channel manifest"; return 1; }
        want_ver="$(_lpJsonStr "$manifest" version)"
        tarname="$(_lpJsonStr "$manifest" url)"
        want_sha="$(_lpJsonStr "$manifest" sha256)"
    fi
    [[ -n "$want_ver" ]] || { isError "lpFetchRelease: could not determine version"; return 1; }
    [[ -n "$tarname" ]] || tarname="libreportal-${want_ver}.tar.gz"

    tmp="$(mktemp -d)"; tar="$tmp/$tarname"
    if ! _lpDownload "$base/$channel/$tarname" "$tar"; then isError "lpFetchRelease: download failed ($tarname)"; rm -rf "$tmp"; return 1; fi
    if [[ -z "$want_sha" ]]; then
        _lpDownload "$base/$channel/$tarname.sha256" "$tar.sha256" 2>/dev/null && want_sha="$(cut -d' ' -f1 < "$tar.sha256")"
    fi
    [[ -n "$want_sha" ]] || { isError "lpFetchRelease: no checksum available — refusing"; rm -rf "$tmp"; return 1; }
    got="$(_lpSha256 "$tar")"
    if [[ "$got" != "$want_sha" ]]; then isError "lpFetchRelease: CHECKSUM MISMATCH ($tarname) — refusing"; rm -rf "$tmp"; return 1; fi

    # Signature: verify against the root-owned footprint key (mandatory once the
    # key is real; skipped only for an unsigned/dev build). Shared trust anchor
    # with the artifact-index path — see lpVerifyMinisig above. Fetch the .minisig
    # first (best-effort) so the verifier can find it; the verifier itself decides
    # whether a missing/invalid signature is fatal.
    _lpDownload "$base/$channel/$tarname.minisig" "$tar.minisig" 2>/dev/null || true
    local sigstate
    if ! sigstate="$(lpVerifyMinisig "$tar" "$tar.minisig")"; then rm -rf "$tmp"; return 1; fi
    [[ "$sigstate" == "verified" ]] && isNotice "Release signature verified."

    # Replace the install tree (code only; configs/logs are in the system tree).
    runInstallOp rm -rf "$script_dir"
    runInstallOp mkdir -p "$script_dir"
    if ! runInstallOp tar xzf "$tar" -C "$script_dir" --strip-components=1; then
        isError "lpFetchRelease: extract failed"; rm -rf "$tmp"; return 1
    fi
    rm -rf "$tmp"
    isSuccessful "Fetched LibrePortal $want_ver ($channel) and verified its checksum."
}

# Mode-aware runtime fetch. git/local stay with their existing helpers; this adds
# the release path. Callers (updater/reinstall/reset) decide pre/post (config
# backup, redeploy) around it.
lpFetchSource() {
    case "${CFG_INSTALL_MODE:-release}" in
        release) lpFetchRelease "$@" ;;
        local)   declare -f copyFilesFromLocal >/dev/null 2>&1 && copyFilesFromLocal ;;
        git)     declare -f gitFolderResetAndBackup >/dev/null 2>&1 && gitFolderResetAndBackup ;;
        *)       isError "lpFetchSource: unknown CFG_INSTALL_MODE '${CFG_INSTALL_MODE}'"; return 1 ;;
    esac
}

# Semver-ish compare: lpVersionGt A B  → true if A > B (numeric dotted compare,
# trailing non-numeric ignored). Used by the updater + the badge generator.
lpVersionGt() {
    local a="${1%%-*}" b="${2%%-*}" i x y
    local -a A B; IFS='.' read -r -a A <<< "$a"; IFS='.' read -r -a B <<< "$b"
    for ((i=0; i<${#A[@]} || i<${#B[@]}; i++)); do
        x=$((10#${A[i]:-0} + 0)) 2>/dev/null; y=$((10#${B[i]:-0} + 0)) 2>/dev/null
        (( x > y )) && return 0
        (( x < y )) && return 1
    done
    return 1
}